Frames for windows and the like have traditionally been made from wood, and the manufacturing process has often involved fairly complex machining operations both in providing the frame members with the desired profile and in forming the corner joints of the frames. These machining operations result in a considerable wastage of material. Furthermore wooden frames require frequent painting to avoid rapid deterioration from exposure to the weather.
As an alternative to wood, it is also well-known to manufacture frames for windows and the like from aluminium, which may be extruded to provide suitable profiles, usually of complex cross-sectional shape, which may be cut into frame members of the desired length and assembled by means appropriate corner joint arrangements to provide the required frames. While such frames of aluminium are likely to require less maintenance than frames made from wood, the aluminium frames result in a considerably greater transmission of heat unless the profiles incorporate some form of heat barrier, which further increases the complexity of the profile.
In the interests of ease of manufacture, avoidance of wastage of materials, economy and providing a virtually maintenance-free product it has been proposed to construct frames for windows and the like from wooden frame members of simple cross section (e.g. rectangular) having cladding portions at least partially enclosing the wooden frame members, which cladding portions are conveniently made by extrusion of plastics material and are shaped to perform the necessary sealing, weather resisting and interconnecting roles of the frame. Such cladding can be pre-coloured to perform any decorative function and is virtually maintenance free. The specification of my United Kingdom patent application No. 7924197 (published under No. 2026125 on Jan. 30, 1980) relates to the formation of corner joints between frame members and shows, in FIGS. 3 and 7 of the drawings thereof, a cross-section of a frame member (as just above referred to) having a wooden core with a cladding of plastics material extruded therearound for use in the construction of a window frame. The corner joints as disclosed in said specification are made by injecting plastics material into communicating cavities formed in abutting portions of the frame members, the plastics material being reinforced by metal inserts if desired.
It is an object of the present invention to achieve further economies and ease in the manufacture of frames for windows and the like with substantially no wastage of materials by providing a cored extruded plastics profile which is so formed and shaped that, not only can it be manufactured very economically, to very close dimensional tolerances, and with virtually no wastage of material, but, with very simple operations performed thereon, can be used to assemble both an outer, static, frame and an inner, opening frame of a frame assembly for a window or the like which may be fitted with glass or other panel material and readily interconnected by hinge mechanism or the like.